Giant magnetoelectric coupling and e -field tunability in a laminated Ni₂MnGa/lead-magnesium-niobate-lead titanate multiferroic heterostructure

The multiferroic properties of a laminated heterostructure consisting of magnetostrictive Ni₂MnGa ribbon and piezoelectric lead-magnesium-niobate-lead titanate crystal are reported. A tunability of the electric field-induced magnetic field was measured by a shift in the ferromagnetic resonance (FMR) field by 230 Oe at X -band while applying an electric field of 6 kV/cm. Concomitantly, a frequency shift in the FMR of 370 MHz was observed. The sensitive tunability stems from a large linear magnetoelectric coupling coefficient, A=41 Oe cm/kV, measured in the heterostructure. This represents a new class of metallic multiferroic heterostructures that operate at microwave frequencies.